Marsh Sanctuary has a rich history in the Mount Kisco community. The 156-acre property owes the existence of its Greek-style amphitheater to playwright, actress and women's rights activist Martha Leonard, who had it built in the early 1900s and held many plays there into the '20s. The sanctuary's name and additional properties are derived from the family of Norman Marsh. Mr. Marsh memorialized the sanctuary in honor of his nature-loving daughter, Cornelia, who passed away in the 1950s.
Today, Marsh Sanctuary provides a beautiful network of trails and protected lands and wildlife for its many visitors to enjoy throughout the year. Music festivals are held annually in the 350-seat outdoor theater.